On the NETTUTS.com site, there's a new tutorial that looks to be a basic introduction to the world of Object-oriented programming in PHP.

Numerous examples from robots to bicycles have been offered as “easy” explanations of what OOP is. I’ve opted to show you how OOP works with a real-life example, for a programmer. By creating a MySQL CRUD class you can easily create, read, update and delete entries in any of your projects, regardless of how the database is designed.

Their CRUD example not only serves as an introduction to OOP, but can also be an introduction to MySQL support for those that haven't used it before. They create six functions - the four for CRUD and a connect and disconnect. The full source is available for download too.